Image-Forming Device Developing Bias Voltage Control
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Solution Overview
Problem
Conventional image-forming devices face challenges in maintaining consistent image density due to developer deterioration over time, leading to variations in image density despite density correction methods, as the methods do not account for the increasing number of image formations.
Innovation Solution
An image-forming device with a patch forming unit, monitoring, measuring, and correcting units that form and measure patches to determine and apply correction amounts to the image forming conditions, adjusting the developing bias voltage based on the number of image formations to maintain consistent image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If density correction is performed using conventional methods without considering developer deterioration, then initial image density can be corrected, but image density becomes inconsistent as the number of image formations increases
Solution Approach 1:
The patent implements dynamic adjustment of developing bias voltage based on the number of image formations. The control unit modifies the developing bias voltage progressively as the developer deteriorates, transforming the static correction approach into a dynamic one that adapts to developer aging, thereby maintaining consistent image density throughout the developer's lifecycle
Solution Approach 2:
The patent employs feedback mechanisms where image density is continuously monitored and the developing bias voltage is adjusted based on measured density values. This closed-loop control system detects density deviations caused by developer deterioration and automatically compensates by modifying the developing bias voltage, ensuring consistent image quality
2Ease of operation
If equal developing bias voltage is applied throughout operation, then device operation is simple, but image density rises as developer deteriorates
Solution Approach 1:
The patent changes the developing bias voltage parameter progressively as the number of image formations increases. By modifying this electrical parameter in response to developer deterioration, the system maintains optimal image density without requiring complex mechanical adjustments or manual intervention, achieving precision through parameter adaptation
3Measurement precision
If patch density measurement is performed without considering operating state, then measurement process is simple, but correction amount becomes inaccurate as developer deteriorates
Solution Approach 1:
The patent performs preliminary measurement of patch density at regular intervals during operation. By measuring density before significant deterioration occurs and using these measurements to proactively adjust the developing bias voltage, the system maintains accurate correction throughout the developer's lifecycle rather than attempting to correct after deterioration has occurred
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device accurately corrects image density by dynamically adjusting the developing bias voltage, reducing the need for excessive developer usage and extending the lifespan of components, ensuring consistent image quality and reducing developer collection.
Implementation Method 1
an electrostatic latent image is formed on the surface of a photoconductor
Implementation Method 2
a developer is applied to the surface of the photoconductor to form a developer image
Data Source
AI summary
An image-forming device includes an image forming unit, a patch forming unit, a monitor, a measuring unit and a correcting unit. The image forming unit provides an electrostatic latent image formed on a surface of a photosensitive drum with charged developer to form a developer image based on an image forming condition, and transfers the developer image to an recording medium to form an image. The patch forming unit controls the image forming unit to form a patch with the developer. The monitor monitors an operating state of the image forming unit after one patch is formed before next patch is formed. The measuring unit measures density of the patch. The determining unit determines a correcting amount used to correct the image forming condition, based on the measured density of the patch. The correcting unit corrects the image forming condition based on both the correcting amount and the operating state.